Research by the journalist collective 'Lost in Europe' has revealed that at least 51,433 unaccompanied refugee children and young people who were previously in the care of the state went missing across Europe between 2021 and 2023.

The months-long investigation builds on research published in 2021 that showed that more than 18,000 migrant and refugee children went missing in Europe between 2018 and 2020.

According to the data collected in the latest investigation, Italy has more registered missing unaccompanied minors than any other country that provided data, with 22,899, followed by Austria (20,077), Belgium (2,241), Germany (2,005) and Switzerland (1,226).

The actual number of missing migrant children may be even higher, according to a statement by the Lost in Europe project. Gathering complete information is difficult, and some countries in Europe do not collect any data on missing unaccompanied minors, it added.

Also read: Europe’s lost migrant children

Tip of a 'giant iceberg'

Aagje Ieven, the secretary general of Missing Children Europe, a network of grassroots organizations trying to prevent the disappearance and exploitation of children, said the figures were "worrying".

"The increased number of reports on missing unaccompanied minors serves as a sharp reminder of the giant iceberg that looms beneath the surface," Ieven told Lost in Europe.

Ylva Johansson, the EU Commissioner for Home Affairs responsible for migration, in an interview with the German news portal rbb24 – a member of the Lost in Europe network – linked the problem to Europe’s "broken migration system".

She warned that the children concerned could become victims of human traffickers.

Also read: 'More than 200' migrant children went missing in the UK, admits minister

Child protection organizations like Missing Children Europe have confirmed that unaccompanied child migrants and refugees are at higher risk of abuse and are easily influenced by traffickers.

Many who arrive in Europe have already been exploited by smugglers to pay off debts or because they hold control over their loved ones or their passports, CNN quoted Ieven as saying.

It notes that a 2022 study by researchers at Ghent University – The Childmove Project – found that more than 80 percent of children experience physcial violence during their migration to Europe.

Also read: Missing children: 'If they weren't migrants, everyone would panic'

'Crisis in child protection'

Patricia Durr, chief executive of ECPAT UK, told Lost in Europe that the current crisis in child protection is exacerbated by strict border policies and "the lack of safe and legal routes for children in Europe to move between member states safely."

Durr also said children’s vulnerability would be increased by the EU’s new Pact on Migration and Asylum, through introducing "measures such as including children within detention for screening purposes."

The Pact’s supporters hope the introduction of a central system for registering unaccompanied migrant children will help to solve the problem of minors going missing within the EU.

For Ieven, registering children is key to their safety, combined with an acknowledgment of their rights.

She adds that success hinges on migrant children knowing that "there is a future for them in the system, rather than outside of it."